Seniors

Effects of age on cutaneous circulatory response to direct heat on the forearm

Article Abstract:

With aging, the body's mechanisms for regulating temperature undergo changes. Blood flow under the skin (cutaneous circulation) is also altered by aging, and it has been suggested that the changes in these two processes may be related. Studies have been done in which subjects were exposed to high heat and the blood flow in the forearm was measured. Differences among young, middle-aged, and elderly subjects have been found in the forearm blood flow response to heat stress, but the results of various studies have been inconsistent. In this study, adult male subjects of three age groups (20 per group) volunteered to have their forearm blood flow measured by a Doppler flowmeter, which detects red blood cell flow through the blood vessels. Instead of exposing the entire person to heat, their forearms were placed in a water bath. When water temperature was increased from 30 to 40 degrees Celsius, cutaneous blood flow increased significantly. However, blood flow velocity was significantly lower in the older (age 60 to 79) and middle-aged (age 40 to 59) groups than in the young (age 20 to 39) subjects. The results indicate that aging causes a decrease in cutaneous blood flow response to direct heat applied to the forearm. (Consumer Summary produced by Reliance Medical Information, Inc.)

Thermally-induced cutaneous vasodilatation in aging

Article Abstract:

The cutaneous blood flow response to local heating was compared between a group of 43 healthy, ambulatory older people and a group of 39 young adults using the laser Doppler technique. Results showed that at 35 degrees centigrade, there was minimal difference in skin blood flow between the two groups. On the other hand, skin blood flow at 44 degrees centigrade at nutritively perfused sites was lower in older subjects while blood flow at arteriovenous anastomic flow sites such as the finger or toe pulp did not differ between the two groups. Moreover, local heating of nutritive sites resulted in decreased microvascular volume and red blood cell velocity.

Attenuation of the cutaneous vasoconstrictor response to cold to elderly men

Article Abstract:

The cutaneous vasoconstrictor response in the elderly was compared in young men by measuring regional blood flow in their fingertips using laser Doppler flowmetry and by measuring blood cell velocity using videodensitometry before and after cooling of the contralateral arm. Decreased regional blood flow was observed after one minute in both groups. Four minutes of cold stress resulted in subsequent depression of regional blood flow in the young subjects while theold group had pre-cooling values. Blood cell velocity during cooling was significantly changed in the young group in contrast to the old group.